The present invention relates to a data transfer control device and an electronic instrument.
In recent years, the Serial AT Attachment (Serial ATA) standard has attracted attention aimed at a serial interface for storage devices and the like. The Serial ATA standard has software-level compatibility with the Parallel ATA (IDE) standard. The data transfer rate of the original Serial ATA I standard is 1.5 Gbps. In the next Serial ATA II Gen2 standard, the data transfer rate is increased 3.0 Gbps. The number of interconnects provided between circuit boards included in an electronic instrument can be reduced utilizing the Serial ATA standard, whereby the size of the electronic instrument can be reduced.
On the other hand, a host (host device or host board) of an electronic instrument includes a parallel ATA (hereinafter appropriately referred to as “PATA”) interface (hereinafter appropriately referred to as “I/F”), but generally does not include a Serial ATA (hereinafter appropriately referred to as “SATA”) I/F. Therefore, a SATA device cannot be connected to a host which includes only a PATA I/F.
Devices such as a hard disk drive (HDD) have been increasingly equipped with a SATA I/F instead of a PATA I/F. Therefore, it is difficult to obtain an HDD equipped with a PATA I/F. As a result, the type of HDD which can be connected to a host which includes only a PATA I/F is limited, whereby an increase in capacity of a built-in HDD of electronic instruments is hindered.
The AT Attachment Packet Interface (ATAPI) standard is known as an interface standard for multimedia devices such as CD drives and DVD drives. The ATAPI standard employs a packet command concept in order to minimize the expansion of ATA commands. According to the ATAPI standard, a device other than an HDD can be connected to an HDD ATA (IDE) controller. Therefore, when providing a data transfer control device with a PATA/SATA bridge function, it is desirable that the data transfer control device appropriately implement ATAPI data transfer.
JP-A-2005-346123 and JP-A-2006-121621 disclose a SATA/PATA bridge IC. JP-A-2005-346123 and JP-A-2006-121621 disclose inventions relating to a circuit board using the bridge IC and the like, but do not disclose an invention relating to a specific configuration of the bridge IC.
JP-A-2006-18428 discloses an HDD including a SATA bridge. The SATA bridge disclosed in JP-A-2006-18428 is a bridge in which a host is connected to the SATA side and a device is connected to the PATA side. Specifically, JP-A-2006-18428 does not disclose an invention relating to a bridge in which a host is connected to the PATA side and a device is connected to the SATA side. JP-A-2006-18428 discloses an invention characterized by protocol control using firmware, but does not disclose a characteristic circuit configuration.